The Echinoid Directory

Pronechinus Kier, 1965, p. 461

Diagnostic Features
  • Test up to 55 mm in diameter; flattened and discoidal in shape with marked change between aboral and oral plating; pentagonal in outline.
  • Apical disc small; monocyclic; genital plates larger than ocular plates. One genital plate pierced by hydropores; all genital plates with multiple gonopores arranged as an arc.
  • Ambulacra on aboral surface relatively narrow and straight; composed of 6 columns of small hexagonal plates in the type species, each with a pore-pair; no tubercles. On the oral surface ambulacral zones greatly expanded and forming most of the surface, with 6 columns of hexagonal plates; pore-pairs in outer two columns of two kinds - alternately small pore-pairs without peripodial rim, and large circular pore-pairs with pronounced peripodial rim. Pore-pairs of inner column entirely small. Ambulacral plates imbricate adorally.
  • Interambulacra with up to 6 columns of rhomboidal plates, imbricating strongly adapically. Adorally the interambulacra are greatly constricted narrowing to a single column and not reaching the peristome.
  • No primary tubercles aborally, only secondary granulation. Primary tubercles present adorally on interambulacral and ambulacral plates; no pronounced areolar depression; scattered secondary tubercles on interambulacral plates.
  • Primary spines short and simple.
Upper Permian, Turkey.
Name gender masculine
Pronechinus anatoliensis Kier, 1965, p. 462, by original designation.
Species Included
  • Only the type species.
Classification and/or Status

Stem group Echinoidea; Proterocidaridae.



Similar to Proterocidaris in having the adoral and adapical surfaces very different and in the greatly expanded adoral ambulacral zones. Differing from that taxon in having two types of pore-pair on oral ambulacral plates, small simple pore-pairs as well as large circular pore-pairs.

Kier, P. M. 1965. Evolutionary trends in Paleozoic echinoids. Journal of Paleontology 39, 436-465, pls 55-60.